1. Field of the Invention
This invention relates to a mirror device for an automobile; and more particularly; to the mirror device which has a cleaning apparatus for removing water drops from a front surface of a mirror member.
2. Description of the Prior Art
A conventional mirror device for an automobile is disclosed in Japanese Patent Laid Open Publication No. 2 (1990)-41950 published without examination on Feb. 13, 1990 (shown in FIG. 10).
A mirror 1 is positioned at a front side of a holder 2. A hook 3 is formed as part of the holder 2. The hook 3 engages a front surface 1a of the mirror 1. An elastic member 4 is arranged between a back surface 1b of the mirror 1 and the holder 2. The elastic member 4 presses against the mirror 1. As a result, the mirror 1 is vibratably held to the holder 2 at an outer circumferential portion of mirror 1 by the hook 3 and the elastic member 4. A vibrator 5 is fixed against the back surface 1b of the mirror 1. When the vibrator 5 operates, the vibration of the vibrator 5 is transmitted to the mirror 1. Thus, the mirror 1 vibrates. Therefore, water drops on the front surface 1 a of the mirror 1 are removed from the front surface 1a of the mirror 1 by misting and dropping out of the water drops.
The prior art of FIG. 10 has drawbacks, in that a:
gap forms between the hook 3 and the front surface 1a of the mirror 1 because of manufacturing tolerances, there is strain on the holder 2. Also because of design parameters produced by the mirror 1 and holder 2, the curvature value of the mirror 1 does not agree with a curvature value of the holder 2. As a result, the water drops which drop off the front surface 1a of the mirror 1 by initial vibration of the mirror 1 gather in the gap. The water drops which gather in the gap are then transferred again to the front surface 1a of the mirror 1 by additional vibration of the mirror 1.